Ames, Iowa, USA
October 8, 2025
Dr. Denis McGee, professor emeritus in the Department of Plant Pathology, Entomology, and Microbiology (PPEM) at Iowa State University, passed away on September 27 at the age of 86. A member of the ISU faculty from 1978 to 2005, McGee left a lasting legacy at the Seed Science Center (SSC) and in the global seed health community. But for Seed Pathology Professor Dr. Gary Munkvold, McGee was more than a valued colleague.
“For the past 19 years, I have had the honor and privilege to follow in Denis’ footsteps as his successor in seed pathology at ISU,” Munkvold said. “I still occupy his old office and lab in the Seed Science Building. He was a great mentor, role model, and friend.
McGee was known as a pioneer in seed pathology whose influence continues to shape how the industry thinks about seedborne disease management and seed trade. He was instrumental in establishing scientific foundations for seed health testing and in promoting the idea that phytosanitary decisions must be based on solid research rather than politics.
During his tenure at Iowa State University, McGee broadened the scope of the seed program to include pathogen epidemiology, improved methods for detecting seed-borne pathogens, and enhanced the understanding of how seed storage conditions affect pathogen viability and seed quality. His program’s influence reached far beyond Ames.
McGee was recognized internationally as a leader in seed pathology education and research. He trained and mentored countless seed health professionals around the world, sharing his knowledge generously and always emphasizing practical, science-based approaches. This included Dr. Charles Block, current seed health testing coordinator at the SSC and co-director of the National Seed Health System (NSHS).
“Denis urged me to strongly consider returning to grad school for a PhD and that I should study under him,” said Block. “I was working full-time and had a young family, but after a few months, I took him up on the offer. It took 5-6 years to complete, as I continued to work full-time, but that degree turned out to be life-changing.”
McGee’s courses and workshops in countries like Nigeria, Egypt, Ukraine, Albania, Japan, Mexico, Brazil, Colombia, and Uruguay helped build global capacity for seed health testing.
His work with the Center for Agricultural and Biosciences International (CABI) led to the development of electronic databases that consolidated global plant disease information; tools that continue to inform phytosanitary policies and seed health standards today. His collaborations also contributed to improvements in international seed trade standards, ensuring that science and collaboration guided global decision-making.
Among McGee’s notable publications were his highly regarded reference books on maize and soybean diseases, resources that remain valuable to seed technologists and pathologists worldwide. His research on the epidemiology of seedborne diseases, particularly in maize, laid the groundwork for understanding disease transmission through seed systems.
Beyond his research and teaching, McGee was recognized for his steady leadership and international diplomacy. He played a pivotal role in the creation of the NSHS, a government-industry partnership formed to standardize and improve seed health testing in support of fair and science-based trade. He helped bridge the gap between science, regulation, and commerce at a time when the seed industry was rapidly globalizing. He is noted for his remarkable ability to bring people together, scientists, regulators, and business leaders.
Through his decades of work, McGee helped resolve numerous international phytosanitary disputes, always advocating for science-driven, cooperative solutions. His tireless dedication to improving global seed health continues to inspire those who follow in his footsteps.
“Denis was an accomplished scientist and a worldwide leader in the area of seed pathology,” said Block. “But he also had a large impact on the personal side, leaving many memories and stories with the people in his sphere.”
Denis McGee’s leadership, mentorship, and commitment to science-based agriculture have left an enduring mark on the global seed community. His life’s work continues to inspire every researcher, student, and professional carrying his vision forward.
“I will miss him, although there are many traces of Denis’ presence here; his files that I kept, books I inherited from him, 35mm slides of fungi and plants, et cetera,” Munkvold said. “I am reminded of him almost daily, and I am proud to continue building on his legacy.”
Topics
Species
